To meet future energy demand growth and replace older or inefficient units, a large number of fossil fuel-fired plants will need to bebuilt worldwide in the next decade. Yet CO2 emissions from fossil-fired power generation are a major contributor to climate change. As a result, new plants must be designed and operated at highest efficiency. The case studies in this report respond to a request to the IEA from the G8 Summit in July 2005 to illustrate the degree of efficiency now achieved in modern plants in different parts of the world using various grades of fossil fuels. The plants were selected from different geographical areas, because local factors influence attainable efficiency. The results of these analyses show that the technologies for high efficiency (low CO2 emissions) and very low conventional pollutant emissions (particulates, SO2, NOx) from fossil fuel-fired power generation are available now through PCC, IGCC or NGCC at a commercially acceptable cost.